Identification of Reptiles
in the UK
• Six
•
native species
four are widespread
• Several introduced species
•
becoming more common!
Species most likely to be encountered
Common lizard
Slow-worm
Grass snake
Adder
Species less likely to be encountered
Sand lizard
Smooth snake
Red-eared terrapin
Wall lizard
Green lizard
Report aliens at www.alienencounters.org.uk
Common lizard
Males: speckled back & orange belly
Common lizard
Males: speckled back
penile bulge
Common lizard
Females: striped back
Common lizard - juveniles
Initially almost black (born in egg
membrane), soon become bronze
male (speckled)
start to develop adult
markings
female (striped)
Sand lizard
Eyed markings (‘ocelli’)
Males: broad head
green sides in
breeding season
Females: bold eyed markings
Juveniles: tiny but distinct
eyed markings
Slow-worm
Males: typically grey or brown,
lack distinct stripes, may have blue
spots
Slow-worm
Females: dark brown sides,
may have vertebral stripe(s)
Slow-worm
Juveniles: dark sides and vertebral stripe
Slow-worm
Juveniles: usually yellow/gold, but varies through ivory
and pink!
Grass snake
Fast and alert, slender, UK’s largest reptile
Grass snake
Green, grey or brown, usually yellow collar
Grass snake
Round pupils
Grass snake
Females: get bigger,
but shorter tails
Males: smaller, but
longer tails
Grass snake
Eggs usually laid in
manure/compost
juveniles
Grass snake
Usually void foul-smelling liquid from anus if captured; sometimes feign death
Adder
Male: often grey
Female: usually brown
BUT…..can be difficult to sex (and difficult to see tail differences)
Adder
Males: can be bronze/beige but always BLACK zigzag
Adder
Females: always have BROWN zigzag, however dark
Adder
Females: can be ginger, with BROWN zigzag
Adder
Black (melanistic) adders not uncommon
Adder
Juveniles tend to be ginger or reddish
Smooth snake
Paired or barred markings
Males orange underside
Readily strike/bite or do ‘adder head’
Juveniles slender and small
Females – shorter thinner tail
Males – longer thicker tail
Sloughed skins
Scalation (head)
Patterning
Non-native species
Red-eared terrapin
Wall lizard
Green lizard
Photographs
• Photographs used in this presentation are by
Lee Brady, Julia Carey, Jon Cranfield, Terry
Elborn, Chris Gleed-Owen, Fred Holmes, Paul
Stevens and John Wilkinson
• Copyright of all photographs remains with the
photographers and ARC
• These photographs should not be used for
purposes other than NARRS training without
the permission of the photographers.
